EP 0 809 268 B1 describes a circuit breaker having a switch drive, which moves the first arcing contact and also drives the opposite second arcing contact via an auxiliary gear mechanism, which is articulated on the insulating nozzle. For the articulation of the auxiliary gear mechanism, the insulating nozzle has a bead or flange on the outer surface at its first end. A first tensioning ring is pushed on over the bead and is snapped in behind it. From the push-on side, a second tensioning ring is fixed to the nozzle end so as to prevent the first tensioning ring from becoming unlatched. The auxiliary gear mechanism to be driven is fastened to the second tensioning ring. At the opposite second nozzle end, the nozzle is connected to the switch drive by virtue of the fact that the nozzle in turn has a bead or flange at the point at which force is introduced, which bead or flange is clamped in or screwed between two solid force-transmitting component parts. This results in a voluminous holding device for fastening the nozzle to the component parts driven by the switch drive.
In U.S. Pat. No. 5,424,503, an interrupter unit of the generic type for an electrical switching apparatus having a first moveable contact part with an insulating nozzle and a second contact part is disclosed. The insulating nozzle has a tab and is held against said tab by the rated current contact in the form of a clamping holder in the axial direction and pressed against a carrier body. The clamping device also comprises a holding ring, which fixes the end of the rated current contact to the carrier body by virtue of radial clamping.
FR 2 093 339 A has described an electrical self-blowing switch having an insulating nozzle, which is pushed onto a holder and is thus held by virtue of clamping. The insulating nozzle has a two-part design for simplified fitting of the contacts in the switch and comprises a basic body and an attachment piece, both consisting of plastic. Conventionally, the attachment piece has been adhesively bonded to the basic body in seamless fashion. Now, the attachment piece is connected to the basic body such that it can be detached and replaced by an external groove being provided on the basic body and an internal groove being provided on the attachment piece and by an annular wedge engaging in the internal groove and the external groove. The annular wedge is flexible and can have a toothed design on its inside so as to secure it against sliding. This type of flexible wedging allows the lightweight attachment piece to be held in clamping fashion on the basic body, but would be unsuitable for holding the insulating nozzle on the component part in a clamping fashion. Since the annular wedge is arranged in a zone which is subjected to a strong field, it should also consist of plastic. During fitting, the annular wedge is inserted through an opening into the internal groove and external groove in order to wedge the attachment piece and the basic body with one another.